Mesomysis czerniavskyi Sars, 1893, Mesomysis kowalewskyi Czerniavsky, 1882, Mesomysis lacustris, Serrapalpisis lacustris

Body length at maturity ranges from 8 to 17 mm (Audzijonyte et al. 2006). The mean body length of adults just after reaching maturity is about 8.7 mm (Lesutiene et al. 2007). Females are typically 10–16 mm while males are typically 7–9 mm (Komarova 1991).

Nonindigenous Occurrences: In the early 1960s, this species was intentionally introduced into the Curonian Lagoon of the Baltic Sea, Lithuania and Lake Balkhash, Kazakhstan for the purpose of fish food enrichment (Leppäkoski et al. 2002; Pueppke et al. 2018). It was also introduced into various inland water reservoirs of Russia as a means of supporting commercial fisheries (Komarova 1991; Lesutieneet al. 2007), including Bukhtarma Reservoir (Yangina 2016). Since then, it has spread to the Irtysh River (Yangina 2016). As of 2017, Paramysis lacustris has spread into the Hungarian portion of the Danube River (Borza et al. 2019).

Juvenile Parmysis lacustris is typically detritivores/planktivorous, while adults are omnivores with a propensity for carnivory, especially in environments with higher productivity where individuals have higher nitrogen demands (Arbaciauskas et al. 2013; Berezina et al. 2017). Hence, the trophic distance between the largest and smallest individuals of P. lacustris has been observed to be nearly as high as one whole trophic level (Lesutiene et al. 2007).

Potential pathway of introduction: Transoceanic shipping (ballast water)

Paramysis lacustris has been observed in ballast waters of ships in the North Sea (Gollasch 2002) and is considered to have the potential for introduction to the Great Lakes via European ballast water transport (Ricciardi and Rasmussen 1998). Parmaysis lacustris showed a mortality rate of 60% after 24 hours of exposure to a salinity of 19 PSU, and a mortality rate of 100% with exposure to 23 PSU (Ovcarenko et al. 2006). Considering this relatively high short-term salinity tolerance, ballast water regulations requiring salinities of at least 30 PSU are believed to be an appropriate means of control (Ovcarenko et al. 2006). More recently, under current mandatory ballast water regulations (flushing with at least 30 ppt), the risk of entry for this particular species has been modeled as low due to these physiological salinity constraints (Grigorovich et al. 2003). In the 1950s–1970s, Paramysis lacustris was one of the most popular species of intentional transplantations as forage for commercial fish into Eastern European water bodies (Arbaciauskas et al. 2010).

Paramysis lacustris has a moderate probability for establishment if introduced to the Great Lakes (Confidence level: Moderate).

Paramysis lacustris is recognized as a stenohaline species, typically occurring in salinities of 0-3 PSU (Komarova 1991; Daneliya 2002); however, it has been able to survive short-term salinity exposures of up to 24 PSU (Santagata et al. 2008). A particular trait of P. lacustris that causes increased concern over invasion is its adaptation to water temperatures up to 20°C, while the coldwater mysids already present in the Great Lakes only tolerate temperatures of up to about 10°C (Bondarenko and Yablonskaya 1979). Paramysis lacustris has been known to survive in situ in temperatures up to 28°C (Baychorov 1980), although this may not be the upper bound for survival (Horan and Lupi 2003). This species can tolerate up to 110 days of ice cover per year (Olenin and Leppäkoski 1999), and is thus expected to have the ability to overwinter within the Great Lakes. The effects of climate change (warming water temperatures) are likely to have a positive effect on this species as compared with Great Lakes native mysids due to its greater degree of adaptation to warm, shallow waters (Bondarenko and Yablonskaya 1979; Ricciardi and Rasmussen 1998).

The range of this species has showed continued expansion throughout the waters of Eastern Europe and Russia over recent decades (Mordukhai-Boltovskoi 1979a,b; Salemaa and Hietalahti 1993), and it has become numerically dominant by biomass in invaded communities (Olenin and Leppakoski 1999). This species has been intentionally transplanted with great success into many lakes and reservoirs in Eurasia and the Baltic Peninsula, where it has rapidly formed dense populations (Mordukhai-Boltovskoi 1964, 1979a). Paramysis lacustris is currently common in the inland waters of Lithuania, Latvia, and Estonia (Arbaciauskas et al. 2010) and its further expansion is considered inevitable (Borza and Boda 2013).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Beneficial

In the Baltic Sea, P. lacustris has significantly modified invaded habitat through pelletization of the substrate (Olenin and Leppakoski 1999).

There is little or no evidence to support that Paramysis lacustris has the potential for significant socio-economic impacts if introduced to the Great Lakes.

Biomagnification of contaminants in higher trophic levels would likely occur as the result of a lengthening in food chain length where this species invades (Ricciardi and Rasmussen 1998). This would result in higher PCB and mercury levels in pelagic fish, causing potential harm to commercial fisheries. Studies have already shown mercury and PCB levels to be significantly higher in North American mysid-containing lakes as opposed to mysid-free lakes (Rasmussen et al. 1990; Cabana et al. 1994). However, the scale of the resulting economic effects on fisheries is unknown.

Paramysis lacustris has the potential for moderate beneficial impact if introduced to the Great Lakes.

Paramysis lacustris has been recognized as an important food source for many fishes (Ricciardi and Rasmussen 1998), and was intentionally introduced into many lakes and reservoirs in the Baltic Peninsula to support commercial fisheries in the early 1960s (Komarova 1991; Arbaciauskas 2002; Leppäkoski et al. 2002; Mordukhai-Boltovskoi 1964; 1979a). This species also serves as an important food source for fish (e.g., Perca fluviatilis and Sander lucioperca) and thus may be consumed by species in the Great Lakes (Rakauskas 2019). However, long-term positive effects on fish production have not been proved (Arbaciauskas et al. 2010).

*Ballast water regulations applicable to this species are currently in place to prevent its introduction to the Great Lakes. See Title 33: Code of Federal Regulations, Part 151, Subparts C and D (33 CFR 151 C) for the most recent federal ballast water regulations regarding the control of nonindigenous species within the Great Lakes and Hudson River.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control

Biological
There are no known biological control methods for this species.

Physical
There are no known physical control methods for this species.

Chemical
There are no chemical control methods for this species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.

The long history of intentional transfers of P. lacustris through Eastern Europe has resulted in a lineage with unique gene and trait combinations that may promote invasion success relative to the Ponto-Capsian lineage (Audzjonyte et al. 2017).